Plumbing contractor insurance in Maryland

Maryland's plumbing board and the local license layer

The Maryland State Board of Plumbing licenses plumbers statewide. It sits in the Maryland Department of Labor (Maryland State Board of Plumbing).

The board's main license levels:

• Apprentice plumber/gas fitter, from age 16
• Journey plumber/gas fitter, after four years as an apprentice, 7,500 training hours under a master and 32 hours of backflow prevention testing
• Master plumber/gas fitter, after two years as a journey plumber plus 3,750 hours under a master
• Limited master and limited journey licenses, which are restricted by geography

State licenses expire May 1 of odd-numbered years, on a two-year cycle.

Two local systems run alongside the state. WSSC Water issues its own plumber and gasfitter licenses in its district, which covers Montgomery and Prince George's counties, so plumbers based in Rockville apply to WSSC separately. A passing exam score isn't forwarded for you. Baltimore County also licenses plumbers. The State Board reciprocates with WSSC and Baltimore County licenses when you hold both the plumbing and gas portions.

Working without a license is expensive. The board lists fines of up to $100 a day, up to six months in jail for each day, or both, or up to $5,000 per violation.

The insurance duty falls on the master who contracts, not on apprentices or journey plumbers. If you're a master working for someone else's shop, the employer's policy can satisfy the rule for that work. It doesn't reach side jobs you take on your own, so a master doing weekend work for cash needs a policy of his own.

The board's pages list no state license bond. Ask about permit bonds in each county where you pull permits.

How Maryland handles workers' comp for plumbing crews

Maryland starts from a presumption. Anyone working for you under a contract of hire or an apprenticeship is treated as a covered employee unless you prove that person is an independent contractor under common law. There's no small-employer cutoff for plumbing shops.

Maryland's Workplace Fraud Act adds a second test where it applies. Paid work is presumed to create an employer-employee relationship unless the employer proves all three parts: the worker is free from control, runs an independent business of the same kind, and does work outside your usual course or place of business. A 1099 helper who rides in your van rarely clears that bar.

If you do use true subcontractors, get a current workers' comp certificate from each one before the first day on site and keep it with the job file. At audit, a sub without proof of coverage can be counted on your payroll, rated in the class of the work that sub did.

Paid corporate officers and LLC members count as covered employees, but some can opt out. Officers of close corporations, officers of other corporations under certain conditions, and LLC members with at least a 20% profits interest may elect an exemption. The business files written notice with the Workers' Compensation Commission (Maryland Workers' Compensation Commission) and its insurer.

Failing to secure coverage is a misdemeanor in Maryland, with a fine of up to $5,000, up to a year in jail, or both. For a corporation, the officer in charge of general management is the one liable. Set up workers' comp for your plumbing crew before your first hire starts. Get a quote for your plumbing business →

The risks behind Maryland plumbing premiums

Rowhouse-era plumbing in Baltimore

Baltimore's housing is old by any measure. Of its 295,032 units, 41.5% were built in 1939 or earlier, two-thirds predate 1960, and only 9.1% went up after 2000. Old supply lines and cast-iron drains turn routine repairs into water damage risks, and completed operations coverage handles damage that shows up after you've left.

Example scenario: A plumber sets a new toilet flange in a Baltimore rowhouse and leaves on a Friday. Three weeks later the wax seal fails, and water stains the ceiling of the unit below. That later damage is a completed operations claim, the exact coverage Maryland's license law requires.

Rising tidal flooding

NOAA's Annapolis tide station averaged about 10 high-tide flood days a year from 2015 to 2024, up from fewer than one a year between 1930 and 1989, and it logged 27 in 2024. Saltwater in basements reaches water heaters, mechanical rooms and any gear stored low.

For waterfront remodels, think about the materials too. Fixtures and water heaters staged in a low garage before install can be lost to a single high tide, and an installation floater is built for property you're installing until the job is accepted.

Misclassified helpers

Between the comp presumption and the Workplace Fraud Act, a crew built on 1099 helpers is an audit risk. If those workers are reclassified, their pay can be added to your payroll after the policy year and billed at your rate. Our workers' comp audit guide shows how to prepare.

Maryland cities we serve

Cost drivers for Maryland plumbing insurance

In Maryland, completed operations isn't optional for a contracting master. A cheaper policy that excludes or sublimits completed operations wouldn't meet §12-501, so don't let a low quote talk you into one. And because umbrella limits don't count toward the minimum, the primary policy itself has to carry the statutory limits.

Beyond that floor, contracts set the number. Commercial GCs and property managers often require more than a typical $1 million per occurrence and $2 million aggregate policy, usually met with an umbrella. Comp cost follows payroll and class, so how you classify your crew matters as much as how many people you employ.

Timing matters at renewal. Because Maryland licenses expire on May 1 of odd-numbered years, line up your liability renewal so the certificate the board sees is current when you renew the license.

Your price depends on payroll, revenue, claims history, the work you do and the limits you choose. Our plumber insurance cost guide lists national medians for each policy. Get a quote for your plumbing business →

Licensed in Maryland

Plumbing Insurance Group is a brand of The Allen Thomas Group, licensed in Maryland (License #3003445098, NPN 7642818). We quote plumbing contractors from the Eastern Shore to Western Maryland.